The 54 paintings -- whose insured value totals over $1 billion -- were seized by Swiss customs officers as they were returning to Russia by truck after a three-month exhibit at the Pierre Gianadda Foundation, in the town of Martigny.
They include works by renowned French artists such as Nicolas Poussin, Claude Monet, Pierre-Auguste Renoir, Paul Gauguin, Henri Matisse, and Paul Cezanne, as well as paintings by Spain's Pablo Picasso.
Igor Petrov, the press attache of the Russian Embassy in Switzerland, confirmed to RFE/RL's Russian Service that the Noga firm had engineered the paintings' seizure.
"Yesterday, for the first time, the decision to seize these paintings was cancelled due to intervention of the federal council of the Swiss government," Petrov said. "[At that time] the trucks [with the paintings] probably were on their way to the border. Meanwhile, on behalf of the lawyers of the Noga company another claim for the confiscation [of the paintings] was issued. It was very quickly examined -- very quickly a positive decision was made -- and it was this second ruling that meant the trucks were kept at the border."
Neither representatives of Noga nor the firm's lawyer were available for comment today.
Noga, an import-export firm based in Switzerland, claims Russia owes it $680 million in unpaid debts from oil-for-food deals signed in the early 1990s. Russia denies any wrongdoing and says the debts were connected to the former Soviet Union.
The paintings' seizure is Noga's latest attempt to recover the purported debt by snatching Russian assets abroad.
In 2000, the firm impounded a famous Russian sailing ship that was due to take part in a regatta in France. Then it had the accounts of the Russian Embassy in Paris frozen.
Both actions were ended by courts ruling in favor of Russia.
But these first failures did little to dampen Noga's resolve. In 2001, it tried to appropriate two Russia military jets during the prestigious Le Bourget airshow in France, but the attempt was foiled.
Noga's latest move has sparked outrage in Russia.
The Federal Culture and Cinematography Agency has slammed it as "a gross violation" and instructed all Russian museums to suspend talks with their Swiss partners on future exhibitions until the row is solved.
The incident sparked an heated discussion at the State Duma this morning, and Finance Minister Aleksei Kudrin has denounced the arrest as illegal.
But most distressed of all is the director of the Pushkin Fine Arts Museum, Irina Antonova, who said the paintings have become "hostage to political or economic machinations."
She told Russian television she fears the paintings could suffer damage from temperature and humidity changes, since the trucks' air-conditioning had been turned off following the impoundment.
Swiss authorities, she added, also illegally confiscated the passports and cellular phones of the museum workers accompanying the works of art.
Larissa Korabelnikova is a senior spokeswoman for the State Hermitage Museum in St. Petersburg. She said this is not the first time works of art have been confiscated as a result of inheritance or economic disputes:
"These things happen. It is very sad, because then we simply won't be able to exchange exhibitions," Korabelnikova said. "All museums in all countries have different agreements. In some countries such arrests are permitted, in others they are not."
The case was to be reviewed by a Geneva court today.